Marine campaigners fight Bight exploration

Conservationists say a threat to marine life from oil exploration in the Great Australian Bight will extend well beyond larger marine creatures.

BP has been granted four exploration licences in the Bight region.

Conservationists say whales, dolphins and tuna could be put at risk.

Michelle Grady from the Save Our Marine Life alliance says there is emerging evidence that seismic testing can harm the food chain.

"There are increasing concerns about the impact of seismic exploration on other marine life including scallops and shellfish," she said.

"The Tasmanian scallop industry recently raised the red flag about two out of three of their scallop beds in Bass Strait. After seismic exploration the scallops died."

She said the worries needed to be taken seriously.

"We certainly know that massive blasts of sound into the water can impact marine life and we're talking about economically important species here as well as marine life more broadly," she said.

The Victorian Government and the company involved denied seismic testing caused the die-off.

Primary Industries said an environmental report had found no proven impact on scallops of similar creatures from seismic survey work.

A spokesman from testing company Drill Search said his understanding was that sounds from the surface were muffled by the water and when they reached the sea beds the intensity was insufficient to cause harm.